The invention relates to an information processing equipment that manages classified information, a method thereof, and a system using the information processing equipment.
From the viewpoint of information security, business corporations have recently performed as business practices dividing a classified information data file with high confidentiality into a plurality of different data files and storing the thus-divided respective data files into a plurality of different storage locations. Even if an employee of a corporation has lost, while he/she is on the road, a PC (Personal Computer) where one of the divided files is saved, leakage of the original data file can be prevented.
A storage location for these divided data files includes an online storage connected to a user device by way of a network as well as a local storage location like an external storage medium, such as a hard disk drive of a user device (e.g., a notebook PC), an SD card, and USB (Universal Serial Bus) memory. However, the user device consumes a much longer time to read the divided data files stored in the online storage than to read the divided data files stored in the local storage location. Likewise, the user device consumes a much longer time to write the divided data files into the online storage than to write the divided data files into the local storage location.
For these reasons, a technique described in connection with Patent Literature 1, for instance, has hitherto been known as a related art of dividing an original data file into a plurality of different divided data files and storing the divided data files into a plurality of different storage locations. According to Patent Literature 1, a remote site server divides an original file into different sizes of a plurality of files, to thus produce a larger-size first file and a smaller-size second file, and stores the first and second files in a correlated manner. In response to a first acquisition request from a client, the server transmits the first file to the client. Further, in answer to a second acquisition request that differs in time from the first acquisition request from the client, the sever transmits the second file to the client. The client consolidates the first and second files, to thus restore the original file.